The spot from Put Alaska First rips Sullivan for trying to "give government more power over our land and water," and attacks Treadwell for helping to create "a company that helped the government spy on people."

The ad seems designed to hurt both candidates with libertarian-leaning voters in both the primary and general elections, and potentially boost 2010 Senate nominee Joe Miller (R) in the primary.

"Sullivan and Treadwell: More government, less privacy, out of touch with Alaska," the ad's narrator says.

Sullivan has been leading Treadwell and Miller in polls for months, though recent polls indicate a tightening race between Sullivan and Treadwell, and has a huge fundraising advantage over both of his foes.

But Put Alaska First and the Begich campaign have spent nearly $4 million on ads so far, much of them attacking Sullivan and driving his negative numbers up. It seems highly unlikely that Miller could win the primary at this point, but the ad indicates Democrats aren't counting out the possibility of that happening — or are at least happy to try to sow chaos in the race ahead of next Tuesday's primary.

The three GOP candidates also debated on Sunday, sparring over the stimulus, with Sullivan and Treadwell attacking one another for being involved with companies that got stimulus money.